VEHICLE STABILITY CONTROL SYSTEM (for Hydraulic Brake Booster) TRC OFF Indicator Light Remains ON

DESCRIPTION

The skid control ECU is connected to the combination meter via the CAN communication system. Pressing the VSC OFF switch turns off traction control and pressing and holding this switch turns off traction control and VSC. If traction control turns off, the TRC OFF indicator light comes on.

When the temperature inside the hydraulic brake booster becomes too high, the TRC OFF indicator light turns on and traction control is stopped until the temperature decreases.


WIRING DIAGRAM

A00O7IDE01

INSPECTION PROCEDURE

Note


  • When replacing the master cylinder solenoid, perform calibration Click here.

  • As there may be malfunctions in the transfer system related to when the transfer operates in L4, check the transfer system first Click here.

PROCEDURE


  1. CHECK CAN COMMUNICATION LINE


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. Select CAN Bus Check from the System Selection Menu screen and follow the prompts on the screen to inspect the CAN bus (for LHD: Click here, for RHD: Click here.

      OK
      CAN Bus Check indicates no malfunctions in CAN communication.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    C

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    A

  2. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU CSW CIRCUIT)


    1. Disconnect the A7 skid control ECU connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A7-9 (CSW) - Body ground VSC OFF switch not pushed in 10 kΩ or higher
      VSC OFF switch pushed in Below 1Ω

    NG

    CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - VSC OFF SWITCH) Click here

    OK

  3. CHECK TERMINAL VOLTAGE (EXI3)


    1. Disconnect the A7 skid control ECU connector.

    2. A00O4C5E32
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A7-40 (EXI3) - Body ground

      Ignition switch ON

      w/ Rear Differential Lock: Rear differential free

      		 11 to 14 V

    NG

    Click here

    OK

  4. READ VALUE USING INTELLIGENT TESTER (TRC/VSC OFF MODE)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      TRC/VSC Off Mode TRC/VSC off mode/ Normal, TRC OFF or VSC OFF

      Normal: Normal mode

      TRC OFF: TRC OFF mode

      VSC OFF: VSC OFF mode

      		 -

    6. Check that the mode display changes according to VSC OFF switch operation.

      OK
      Display changes according to switch operation.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

  5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - VSC OFF SWITCH)


    1. Disconnect the A7 skid control ECU connector.

    2. Disconnect the G9 VSC OFF switch connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A7-9 (CSW) - G9-6 Always Below 1 Ω
      A7-9 (CSW) - Body ground Always 10 kΩ or higher
      G9-3 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT VSC OFF SWITCH


    1. Remove the VSC OFF switch Click here.

    2. A00O4VVE02
      Text in Illustration
      *a

      Component without harness connected

      (VSC OFF Switch)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      6 - 3 Switch is not pushed 10 kΩ or higher
      Switch is pushed Below 1 Ω
      Result
      Result Proceed to
      NG A
      OK (for LHD) B
      OK (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    REPLACE VSC OFF SWITCH Click here

  7. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU EXI3 CIRCUIT)


    1. Disconnect the A7 skid control ECU connector.

    2. Disconnect the G53 four wheel drive control ECU connector.

    3. w/ Rear Differential Lock:

      Disconnect the E2 rear differential lock detection switch connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A7-40 (EXI3) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (w/o Rear Differential Lock) A
      OK (w/ Rear Differential Lock) B
      NG C

    B

    Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

  8. CHECK TERMINAL VOLTAGE (EXI3)


    1. Disconnect the A7 skid control ECU connector.

    2. Connect the G53 four wheel drive control ECU connector.

    3. A00O4C5E32
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A7-40 (EXI3) - Body ground Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      NG A
      OK (for LHD) B
      OK (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    REPLACE 4 WHEEL DRIVE CONTROL ECU Click here

  9. INSPECT REAR DIFFERENTIAL LOCK DETECTION SWITCH (DIFFERENTIAL LOCK INDICATOR SWITCH)


    1. Remove the rear differential lock detection switch Click here.

    2. A00OBIXE02
      Text in Illustration
      *a

      Component without harness connected

      (Rear Differential Lock Detection Switch)

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 (GND) - 2 (+B) Pushed in Below 1 Ω
      Not pushed in 10 kΩ or higher

    NG

    REPLACE REAR DIFFERENTIAL LOCK DETECTION SWITCH (DIFFERENTIAL LOCK INDICATOR SWITCH) Click here

    OK

  10. CHECK TERMINAL VOLTAGE (EXI3)


    1. Disconnect the A7 skid control ECU connector.

    2. A00O4C5E32
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A7-40 (EXI3) - Body ground

      Ignition switch ON

      w/ Rear Differential Lock: Rear differential free

      		 11 to 14 V

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    REPLACE 4 WHEEL DRIVE CONTROL ECU Click here